It's very easy, and uses pretty much no resources - you won't even notice it running, but can keep it in the corner of your screen in windowed mode to watch it. It ignores the first run (you start it, select a character [.d2s file], but it ignores the first S&E to avoid a longer average time.) It runs in the background. There's really not much to it. Once you run it, you'll see it's very straight-forward, and just there to count the runs.
Not at all. I only ran pindle in windowed mode because he doesn't need a whole lot of focus (tell that to my deedsed sorces...) I just wanted to keep an eye on my number of runs and average time, so that I could try to keep beating my time/keeping it as low as possible.
It'll run in the background without any challenges. When you're done, alt+tab or close D2, and check on the runs. Good luck!
You're running the TC3 tourney? @hackedagainanda - What are you planning to run at the moment?